After a successful login, diplogin (Web hosting service) proceeds by flipping
After a successful login, diplogin proceeds by flipping the serial line to CSLIP or SLIP mode, and sets up the interface and route. This connection remains established until the user disconnects and the modem drops the line. diplogin then returns the line to normal line discipline and exits. diplogin requires superuser privilege. If you don’t have dip running setuid root, you should make dip- login a separate copy of dip instead of a simple link. diplogin can then safely be made setuid without affecting the status of dip itself.